Web feeding and cutting mechanism



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WEB FEEDING AND CUTTING MECHANISM Filed April. 19, 1955 3 Sheets-Sheet 3 /54 44664 A a w 3% 56a, K da /8 f f f V" 5 82a o '/Z v r- /Za l Citt egS WEB FEEDENG AND CUTTING MECHANHSM William C. Schultz, Stillwater, N. Y., assigner to West Virginia Pulp and Paper Company, New York, N. Y., a corporation of Delaware Application April 19, 1955, Serial No. 502,301

7 Claims. (Cl. 164-68) This invention relates to mechanism for cutting substantially identical sheets of paper from superposed travelling webs, the object being to hold variations of length within very narrow limits.

It is common practice to feed from five to ten webs of paper in superposed relation to a flying cutter, so that five to ten sheets are simultaneously cut at each revolution of the cutter knife. Each web is drawn from a separate supply reel, the webs being drawn forward in common by a feed roll couple which consists of a driven feed drum and an opposed idler roller. In order to secure adequate traction the webs are caused to -travel through an arc upon the feed drum.

It is a vwell known fact vthat when superposed sheets or webs are fed around an arc of a cylinder or drum they tend to .travel at uniform angular velocity, the linear speeds of the respective webs being proportional to the radii of the individual arcuate web paths. If sheets are cut at uniform intervals from webs so fed, each outer web will furnish sheets a little longer than the next underlying web and the discrepancy of sheet length between the innermost and outermost webs will be suiciently great `to be importantly objectionable. The maximum difference will be increased with increase of paper thickness, increase of number of webs handled together, and increase of sheet length.

It is the primary object of the present invention to provide a mechanism capable of cutting sheets of substantially equal, predetermined lengths from continuously fed, superposed webs.

To this end it is a feature that a single web-driven squeeze roller is provided in opposition to the web feeding drum, and that means are provided for braking the rotation of the squeeze roller down to a speed such that the outermost web is caused to travel at substantially the same linear speed as the innermost web. The braking action can be applied in various ways, for example, by a simple friction brake controlled by manual, electrical, pneumatic or hydraulic means, or by any driven means which determines the linear surface speed of the squeeze roller in relation to the linear surface speed of the web feeding drum. Such means may consist of an infinitely Variable speed drive for the squeeze roller, a differential drive, a vari-hydraulic drive, or a drag generator coupled to the squeeze roller, together with means for adjusting the retardation to just the value required for equalizing or substantially equalizing the atent web speeds. This latter method is illustrated in the drawrice Other objects and advantages will hereinafter appear.

In nthe drawing forming part of this specification,

Figure 1 is a fragmentary View in side elevation of an illustrative web feeding, lsheet cutting and sheet stacking machine embodying features of the present invention;

Figure 2 is a fragmentary View similar to Figure l but on a larger scale and in more detail than Figure l,- the view being confined to that portion of the machine in which the novel features are incorporated;

Figure 3 ,is a diagrammatic view illustrative of the principle of exercising a retarding effect upon -the squeeze roller by means of a drag generator;

Figure 4 is a detail View on a comparatively large scale showing means for adjustably applying yielding pressure to the squeeze roller bearings;

Figure 5 is a fragmentary view in side elevation of a further embodiment of the invention; and

Figure 6 is a detail plan View of infinitely variable speed drive mechanism employed in the embodiment of Figure 5.

The illustrative machine comprises a bed frame 10 from which a series of pairs of alternately high and low bearing standards 12 and 14 (two shown) extend upward. Each pair of bearing standards supports a reel 16 of paper. Webs 18 are conducted from the various reels into superposed relation, being drawn from the reels and beneath an idler guide roller 2t) by a feed couple which comprises a feed drum 22 yand an opposed squeeze roller 24. The present invention centers around the 4feed couple referred to, and has particularly to do with the retarding effect exercised upon the outer and intermediate webs by the squeeze roller 24.

From the feed couple the webs are thrust forward into the field of action yof a flying cutter which comprises Va stationary knife 26 and an opposed rotary knife 28. The rotary knife is constantly driven at uniform speed, and acts at each revolution to cut olf a length of the web as the rotary knife crosses the stationary knife.

Before cutting, the leading end of the web is carried forward by conveyor mechanism 30. After cutting, the trailing portions of the sheets just cut drop onto the conveyor mechanism. The cut sheets are fed by the conveyor onto a conventional stacker platform 32. The platform is supported by cables 34 and is lowered by the paying out of the cables 34 from a drum 36 as the stacking progresses. The stacker is supported and guided by a frame 38. A motor 4t), through suitable gearing, illustratively indicated by gears 42 and 44, drives a shaft 46 upon which a worm 48 is made fast. The worm 4S drives at greatly reduced speed a worm wheel 50 which is fast upon the shaft 52 of the cable drum 36. The motor 40 is desirably a reversible motor. The present invention is not concerned with details of the stacker. It may be of conventional construction.

The drum 22 and the ying cutter knife 28 are driven from `a main drive shaft 53 through a gear 54 fast on the shaft. The gear 54 drives at constant speed a gear 56 fast on the flying cutter shaft 58. The shaft 58 has fast upon it arms 60 (one shown) by which the travelling knife 28 is carried.

The gear 54 drives the drum 22 through a train of gearing which comprises an infinitely variable speed unit 62. Since units of this kind are conventional and well understood, and the details of the unit form no part of the novelty of the present invention, the adjusting means for the unit is not completely illustrated and will not be completely described.

The gear 54 drives the input shaft 64 of the unit 62 through a gear 66. A cone 68 is mounted on the shaft 64 for rotation in unison therewith. A belt 72 runs upon the cone 68 and also upon a similar cone 74 which is fast upon an output shaft 76. The cones 68 `and 74 are reversed end for end. Rotation of a hand wheel 70 in one direction turns a screw 77 to operate a -belt guiding bail 79 toward the large end of cone 68 and the small end of cone 74, to increase the output-input ratio, and operation of the wheel in the opposite direction has the opposite effect. The unit causes the shaft 76 to be driven at different selected speeds from the constant speed shaft 64. A gear 78, fast on the shaft 76, drives a gear 80 fast on the shaft 82 of the drum 22.

Adjustment of the wheel 70 adjusts the rate of web feed while leaving the rate of operation of the flying cutter unchanged, and thereby adjusts the length of the web fed in a cutting cycle, causing sheets of different selected lengths to be cut.

The squeeze roller 24 runs in contact with the outermost web 18 and hence, if unimpeded, would run at the linear speed of the outermost web as dictated by the feed drum 22. Since, with the squeeze roller 24 running freely, each web would tend to travel at the angular speed of the drum 22, but about a greater radius than the next underlying web, all of the webs would be driven at different speeds and all of the sheets cut at a single operation would be of different lengths, if measures were not taken to overcome that natural tendency.

In order to equalize or substantially equalize the web speeds, the squeeze roller 24 is retarded by connecting it to drive a drag generator 84 whose resistance to rotation may be adjusted as desired. The squeeze roller 24 is made fast upon a shaft 86. The shaft 86 also has fast upon it a gear 88 which, through a chain 90, drives a sprocket 92 fast on a shaft 94. The shaft 94 is connected through a gear unit 96 to drive at greatly multiplied speed a shaft 98 which constitutes the rotor driving means of the drag generator 84. Since the generator shaft 98 is positively geared to the squeeze roller 24, any retardation of the generator is applied proportionally to the squeeze roller 24. The output or load circuit of the generator is made to include a conductor 100, a resistor 102, a slide contact 104 and a conductor 106. By adjusting the slide contact, the generator load, and hence the generator retardation, may be increased or diminished as desired. Such adjustment may be effected while the machine is in operation.

The ideal condition is achieved when the outermost web is slowed down to the linear speed of the innermost web, and the intermediate webs are also slowed down to the same linear speed. In order to achieve the ideal condition, it is necessary that sui'licient pressure be applied to the squeeze roller to transmit the retardation to the outermost web. The shaft'86 is accordingly mounted in bearings 108 which are supported in slots 110 of frame standards 112 with capacity for sliding movement toward and from the axis of the drum 22'. Each bearing is pressed inward by a compression coil spring 114 which bears at its lower end against the bearing and at its upper end against a cup-shaped pressure member 116.

The cup-shaped member is supported on the lower end of a screw 118. The screw 118 is threaded through an outer end portion of the frame member 112 and is provided with an operating hand wheel 120. The hand wheels 120 may be operated while the machine is at rest or in operation, in order to secure the most desirable operating conditions.

The conveyor 30 comprises lower -belts 122 which run upon en'd rollers 124 and 126, and upper belts 128 which run upon end rollers 130 and 132. TheV belts are desirably driven at a linear speed in excess of the speed of the surface of the drum 22. The web develops a small amount of slack between the stationary blade 26 and the point where it is gripped by the upper and lower conveyors. This slack is sufficient to prevent tearing of the web during the instant that the ying cutter is acting to sever the sheet.

In Figure the web feed and cutter drives may advantageously be the same as in Figures 1 and 2, but the retarding means for the squeeze roller is varied, the brake generator being dispensed with and other squeeze roller retarding means being provided. Corresponding reference characters have been applied to the illustrated parts of Figure 5 which are duplicates of the showing of Figures l and 2, with the subscript a added in each instance, and no detailed description of these parts will be given.

For the purpose of controlling the speed of the squeeze roller 24a and hence the speed of the outermost paper web, the drive shaft 82a which carries the feed drum 22a is connected to drive the squeeze roller 24a. The shaft 82a has fast upon it a sprocket 140 which, through a chain 142, drives an input sprocket 144 fast on an input shaft 146 of a speed controlling unit 148. The speed controlling unit 148 may take any one of several forms. As shown in Figure 5, the unit 148 is desirably an infinitely variable speed unit. Tapered pulley sections 150 slidably keyed on the input shaft 146 act through a V-belt 151 to drive a tapered pulley composed of sections 152 slidably keyed on an output shaft 154. Belt shifting means is controlled through an operating handle 156 fast on an adjusting screw 158. The output shaft 154 has fast upon it a sprocket 160 which, through a chain 162, drives a sprocket 164 fast on the shaft 86a of the squeeze roller 24a.

Each of the four pulley sections 150, 152 has circumferentially grooved hub 153. Engaging the groove of each hub is a shifting pin 155. Two of these pins are carried by a lever 157 fulcrumed at 159, and two are carried by a lever 161 fulcrumed at 163. The levers 157 and 161 have slots through which headed pins 165 extend. The pins 165 are fast on nuts 167, which nuts are threaded on right hand and left hand threads of the adjusting screw 158.

Rotation of the screw 158 in one direction separates the pulley sections 150 on input shaft 146 while forcing the pulley sections 152 on output shaft 154 closer together, thereby lowering the output-input ratio of the drive unit, while rotation of the screw 158 in the opposite direction has exactly the opposite effect.

The screw 158 can be adjusted at any time by the hand wheel 156 to bring about any drive ratio desired. The operator can adjust the screw with the machine in operation until the optimum result is seen to be obtained.

As an alternative to-the described variable speed drive the unit 148 may embody a differential gear drive. In this instance the Shaft 146 may be made to drive an input gear of a differential unit, one output gear may be connected to drive the shaft 154, and the other output gear may be connected to drive a shaft (not shown) to which a controlled braking effect is applied, the braking effect being mechanically maintained when the optimum effect upon the paper is seen to be obtained.

As a still further alternative, the shaft 154 may be connected to be driven from the shaft 146 through a variable hydraulic drive of known type. In this instance also, when the optimum condition is obtained, the control device is locked against further adjustment.

A still further variable speed means which may be employed in lieu of that shown in Figure 6 is the wellknown positive infinitely variable drive (PIV) as for example that manufactured by the Link Belt Company of Chicago, Ill.

I have described what I believe to be the best embodiment of my invention. I do not wish, however, to be confined to the embodiment shown, but what I desire to cover by Letters Patent is set forth in the appended claims.

I claim:

l. In a machine for cutting sheets from imperforate paper webs which comprises a series of reels arranged to deliver webs into superposed relation, an equalizing feed couple for drawing the superposed webs forward together in unison including a feed drum upon a segment of which the supelposed webs travel, and a squeeze roller opposed to the feed drum, the combination with the feed drum and the squeeze roller of means for driving the feed drum, means yieldingly urging the squeeze roller toward the feed drum, the construction and arrangeF ment being such that the drum tends t-o drive the webs at different speeds, each proportional to the average radius of its travel about the axis of the drum and to drive the squeeze roller through the webs at a peripheral speed greater than that of the drum, means constructed and arranged to apply an even, continuous retarding force to the squeeze roller suflicient to hold down the linear speed of the outermost imperforate web substantially to the peripheral linear speed of the feed drum, and a paper cutter disposed to act periodically on the superposed imperforate webs after they have passed the bight of the feed couple.

2. The novel combinati-on as set forth in claim 1 in which the means for applying a retarding force to the squeeze roller comprises a slip drag generator, drive gearing for driving the generator rotor from the squeeze roller, and means for adjusting the generator load.

3. The novel combination as set forth in claim 1 in which means is included for adjusting the measure of retardation in accordance with the web thickness and the number of superposed webs acted upon.

4. The novel combination as set forth in claim 1 in which the squeeze roller is driven from the feed drum directly and exclusively through the paper webs and the speed of the squeeze roller is held down by adjustable braking means.

5. In a machine for feeding a group of imperforate webs in superposed relation, and for periodically cutting transversely through the group of traveling, superposed webs to provide successive groups of sheets with every sheet in a group of substantially the same prescribed, uniform length, in combination, a pair of feed rolls between which the group of superposed Webs are fed with an innermost web of said group of webs in contact with a first of said rolls and an outermost web of said group of webs in contact with the second of said rolls, drive means for said first roll, means bearing on the outermost web for directing the group of webs into contact with the surface of said first roll at a point substantially removed from the nip of said feed rolls and causing the group of webs to travel over a substantial segment of said first roll, so that the outermost web travels over an arc of larger radius from the center of said first feed roll than the innermost web, means for pressing said feed rolls toward each other and against opposite faces of said group of webs, means cooperating with the second of said feed rolls for causing the same to travel at substantially the same peripheral speed as said rst feed roll, whereby the innermost and outermost webs will be caused to travel at substantially the same linear speeds, and will thereby induce the intermediate webs also to travel at substantially said same linear speed, and a periodically acting, transverse paper cutter `disposed to cut through the group of webs as they travel forward from said feed rollers.

6. A combination as set forth in claim 5, in which the last stated lmeans is a drive train interconnecting said first and second feed rolls fora desired ratio of rotational speeds. K

7. A combination as set forth in claim 6, in which said interconnecting drive train is a mechanical train.

References Cited in the file of this patent UNITED STATES PATENTS 1,943,752 Wick Ian. 16, 1934 2,484,871 Andreas Oct. 18, 1949 2,571,941 Piper et al. Oct. 16, 1951 2,707,027 Brown Apr. 26, 1955 

